Today (saturday sept. 26th) I started with the original, official image

[yg@localhost RPi]$ wget 'https://downloads.raspberrypi.org/raspbian_latest'
[yg@localhost RPi]$ mv raspbian_latest 2015-05-05-raspbian-wheezy.img.zip
[yg@localhost RPi]$ shasum 2015-05-05-raspbian-wheezy.img.zip
cb799af077930ff7cbcfaa251b4c6e25b11483de  2015-05-05-raspbian-wheezy.img.zip
[yg@localhost RPi]$ /usr/bin/time unzip 2015-05-05-raspbian-wheezy.img.zip
[yg@localhost RPi]$ ls -al
-rw-r--r--.  1 yg   yg   3276800000  7 mai   01:00 2015-05-05-raspbian-wheezy.img
-rw-rw-r--.  1 yg   yg   1038523231  7 mai   17:55 2015-05-05-raspbian-wheezy.img.zip
[yg@localhost RPi]$ shasum 2015-05-05-raspbian-wheezy.img
fd11a319a8e93fc5f93902c67d337ad419706e5e  2015-05-05-raspbian-wheezy.img

and ended up with an image that weights 1/5th of the original archive :

[root@localhost RPi]# sha1sum 2015-09-26_Raspbian_Hardened.3276800000.img
694fc3dca01f8393675d5e7dbc705ec371af7554  2015-09-26_Raspbian_Hardened.3276800000.img
[root@localhost RPi]# gzip -k 2015-09-26_Raspbian_Hardened.3276800000.img
[root@localhost RPi]# sha1sum 2015-09-26_Raspbian_Hardened.3276800000.img.gz
4cec82c359ab7e8d0b74976309f9243f091b819b  2015-09-26_Raspbian_Hardened.3276800000.img.gz
[root@localhost RPi]# l 2015-09-26_Raspbian_Hardened.3276800000.img*
-rw-r--r--.  1 yg   yg   3276800000 26 sept. 06:27 2015-09-26_Raspbian_Hardened.3276800000.img
-rw-r--r--.  1 yg   yg    200269221 26 sept. 06:27 2015-09-26_Raspbian_Hardened.3276800000.img.gz

All the steps are explained there : http://ygdes.com/squeezed/install_20150926.txt

BEWARE ! IT'S CRUDE !

but I'm in a sort of rush because I want to have a complete public and working #SPI Flasher as soon as possible. Since you have all the instructions, you can spot errors, make your own version and send me patches.